This invention relates generally to the field of telecommunications networks and more particularly to a method and system for handling asynchronous transfer mode (ATM) call set-ups.
Telecommunications networks have traditionally been circuit-switch networks that have transmission paths dedicated to specific users for the duration of a call and that employ continuous, fixed-bandwidth transmission. Due to growth in data traffic created by the Internet and its related technologies, however, telecommunications networks are being moved to a packet-switching transmission model. Packet-switch networks provide a large range of digital services, from data to video to basic voice telephony. Packet-switch networks can allow dynamic bandwidth and may be connectionless with no dedicated path or connection-oriented with virtual circuits and dedicated bandwidth along a predetermined path.
Asynchronous transfer mode (ATM) is a connection-oriented packet-switching technology in which information is organized into small, fixed length cells. ATM carries data asynchronously, automatically assigning data cells to available time slots on demand to provide maximum throughput. Compared with other network technologies, ATM provides large increases in maximum supported bandwidth, designed-in asynchronous traffic support, support for multiple types of traffic such as data, video, and voice transmissions on shared communication lines, and virtual networking capabilities, which increase bandwidth utilization with high quality of service and ease network administration.
However, currently implemented methods for handling ATM call set-up requests are inefficient. For example, when a calling party requests a call set-up, a conventional ATM switch may fail to respond to the request before a time-out period expires. When this occurs, the calling party cannot decide how to proceed until after the time-out period, which may result in unnecessary delays in signal processing.
In addition, if the ATM switch eventually does set up a call after the time-out period has expired, the call must be torn down. Tearing down a call requires additional messages between the calling party, the ATM switch and the called party, which utilizes bandwidth and processing power resulting in decreased efficiency for the system.
The present invention provides an improved method and system for handling asynchronous transfer mode (ATM) call set-ups that substantially eliminate or reduce disadvantages and problems associated with previous systems and methods. In particular, a decision regarding a switch""s ability to handle a new call set-up request is provided based on continuously updated data for the switch, allowing a calling party to make a relatively quick decision as to how to proceed if the request is denied.
In accordance with one embodiment of the present invention, a method for handling call set-ups in a telecommunications network. The method includes receiving a request to set up a call. A dynamic load value is compared to a load threshold. The call is allowed to be set up when the dynamic load value is less than the load threshold.
More particularly, in accordance with a particular embodiment of the present invention, the dynamic load value comprises a current load value. An average load value is compared to the load threshold when the current load value is greater than or equal to the load threshold. The call is allowed to be set up when the average load value is less than the load threshold. The request to set up the call is rejected when the current load value is greater than or equal to the load threshold and the average load value is greater than or equal to the load threshold.
Technical advantages of one or more embodiments the present invention include providing an improved method and system for handling ATM call set-ups. In particular, a decision regarding the switch""s ability to handle a new call set-up request is provided based on continuously updated data for the switch. As a result, a calling party is notified relatively quickly if the request is rejected. Accordingly, the calling party may make an informed decision as to how to proceed without having to wait for a time-out period. In addition, the reduced efficiency associated with the use of resources for tearing down calls that are set up after the time-out period is eliminated.
Another technical advantage of one or more embodiments the present invention includes providing an improved ATM switch or other ATM node. In particular, a processing or other suitable card for the switch tracks both current and average load values for the switch, which may be used to handle call set-up requests. As a result, the switch does not become overloaded with a sustained heavy load of call set-ups, but is still able to handle short bursts of requests without rejection. Accordingly, the switch can effectively manage overflow scenarios without running out of internal resources, such as memory.